Assessment of the level and risk of radioactive hazards in coastal sediments in northern Vietnam.

Radioactivity in coastal sediments in northern Vietnam was examined using data from five sediment cores to assess radioactivity concentrations and radiation risk indices. Radiation risk indices included radium equivalent activity (Ra), the absorbed dose rate (ADR), the annual effective dose equivalent (AEDE), the activity utilization index (AUI), the external hazard index (H), the representative level gamma index (I), and the annual gonadal effective dose rate (AGDE). The radioactivity concentrations of K, Th, Ra, U, and Cs were 567, 56.

Assessment of the environmental carrying capacity of pollutants in Tam Giang-Cau Hai Lagoon (Viet Nam) and solutions for the environment protection of the lagoon.

Tam Giang-Cau Hai lagoon is the largest lagoon in Viet Nam. It has two inlets that exchange water with the sea: Thuan An inlet in the north and Tu Hien inlet in the south. Every year, Tam Giang-Cau Hai lagoon receives a large amount of wastewater from five coastal districts with various waste sources such as residences, aquaculture, livestock and industry among others.

-a new species and an updated checklist of Ranunculaceae in Vietnam.

from Ha Giang province, northern Vietnam is described and illustrated. Diagnostic features of the new species are a short rhizomatous stem, (2-)3-foliolate or simple leaves, and pink-purple flowers. The described species is distinct from closely allied in having longer sepals, shape and obcordate apex of petal limbs, shorter flower stem, number and tooth shape of basal leaves; it differs from and in having stem leaf, retuse apex and longer of central leaflet, number and (2-)3-foliated (or simple) of leaf.

Probing topology by "heating": Quantized circular dichroism in ultracold atoms.

We reveal an intriguing manifestation of topology, which appears in the depletion rate of topological states of matter in response to an external drive. This phenomenon is presented by analyzing the response of a generic two-dimensional (2D) Chern insulator subjected to a circular time-periodic perturbation. Because of the system's chiral nature, the depletion rate is shown to depend on the orientation of the circular shake; taking the difference between the rates obtained from two opposite orientations of the drive, and integrating over a proper drive-frequency range, provides a direct measure of the topological Chern number (ν) of the populated band: This "differential integrated rate" is directly related to the strength of the driving field through the quantized coefficient η = ν/, where = 2π is Planck's constant.

Population dynamics of Crenarchaeota and Euryarchaeota in the mixing front of river and marine waters.

A transect from the Tomoe River Mouth through Shimizu Port to Suruga Bay, Japan, was examined between 2005 and 2009 to reveal the population dynamics of Crenarchaeota and Euryarchaeota in an estuary environment. Crenarchaeota tended to increase in abundance in waters deeper than 100 m compared with Euryarchaeota, and comprised 11% of total direct counts. Archaeal abundance was highest in the Tomoe River Mouth, with a strong negative correlation between surface euryarchaeal abundance and salinity (P<0.